Antibody is an arcade shoot 'em up game where players control an antibody trapped inside a platelet, under constant attack by viruses and bacteria seeking to end its existence. The game features a simple control system utilizing the mouse: left-click to shoot in any direction and right-click to move. Players must strategize their movements as any contact with enemies means instant death.

Players are confined to a single setting with enemies continuously spawning, challenging them to accumulate points by surviving as long as possible without perishing. The game offers online rankings to compare points earned. Despite its lack of variety, Antibody provides an engaging experience where precision and skill are key to survival.